REGULATION OF SPERM PROACROSIN CONVERSION TO ACROSIN

在成熟精子中，大多数（如果不是全部）潜在的顶体酶（EC 3.4.21.10）作为无酶活性的酶原前体存在， 顶体蛋白原 由于精子需要酶活性顶体酶才能穿透 卵，前顶体酶必须转化为顶体酶之前，精子可以 达到施肥的能力。 这一更新提案的主要目标是充分表征 前顶体酶，以便确定有关其调节的信息， 可以转化为顶体酶。 这将需要一个详细的 顶体酶原理化性质及其自水解 产品将包括氨基酸序列分析， 可以确定断裂的精确键和断裂的顺序。 这 信息还将用于确定各种因素的具体影响， 转换过程的调节效应。 进一步深入了解 这些转换效应物和顶体蛋白原的关系将是 通过确定它们的结合参数进行研究，它们对 自聚集和大分子构象的变化， 伴随着他们的互动。 可能的生理意义 将确定这些对顶体酶原系统的重要调节剂。 这将包括使用构象特异性抗体， 测量这些成分对顶体蛋白原三级结构的影响， 在细胞水平上。 最后，为了获得一个彻底的 了解新生顶体酶原，以便可以定量系统 以及其转换的规定阐明，将有必要 分离和表征最近在 附睾精子 所有的非酶促转化肽都将被酶促转化。 分析了重要的结构-功能关系， 对顶体酶原转化的调节作用。 这项研究将导致更全面的了解分子 受精所需的事件并最终可能导致可能的 避孕或提高生育能力的控制手段 目的 此外，更全面地了解监管 这种酶原的机制将产生更多的理解， 其他蛋白水解酶系统的可能调节， 重要的生物学过程。

In mature sperm the majority, if not all, of the potential acrosin (EC 3.4.21.10) is present as an enzymatically inactive zymogen precursor, proacrosin. Since sperm require enzymatically active acrosin to penetrate ova, the proacrosin must be converted into acrosin before the sperm can achieve the capacity to fertilize. The primary goal of this renewal proposal is to sufficiently characterize proacrosin so that definitive information regarding the regulation of its conversion into acrosin can be obtained. This will require a detailed physical-chemical characterization of proacrosin and its autoproteolysis products which will include an amino acid sequence analysis so that the precise bonds cleaved and the order of cleavage can be determined. This information will also be used to define specific influences of various regulatory effectors to the conversion process. Further insight into the relationships of these conversion effectors and proacrosin will be investigated by determining their binding paremeters, their influence on self-aggregation and the macromolecular conformational changes which accompany their interactions. The possible physiological significance of these important regulators on the proacrosin system will be determined. This will include the use of conformationally specific antibodies to measure the influence of these constituents on proacrosin's tertiary structure at the cellular level. Finally, to obtain a thorough understanding of nascent proacrosin so that the system can be quantitated and the regulation of its conversion elucidated, it will be necessary to isolate and characterize proacrosin precursors recently identified in epididymal sperm. All of the non-enzymatic conversion peptides will be analyzed for important structure-function relationships so their influence on the regulation of proacrosin conversion can be determined. This study will result in a more complete understanding of the molecular events required for fertilization and could ultimately lead to possible means of controlling it for either contraceptive or fertility enhancement purposes. In addition, a more thorough comprehension of the regulatory mechanisms of this zymogen will produce increased understanding of the possible regulation of other proteolytic enzyme systems which control many important biological processes.